{"id":8462,"date":"2019-05-22T16:07:58","date_gmt":"2019-05-22T16:07:58","guid":{"rendered":"http:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/mosaicism\/"},"modified":"2019-05-22T16:07:58","modified_gmt":"2019-05-22T16:07:58","slug":"mosaicism","status":"publish","type":"post","link":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/mosaicism\/","title":{"rendered":"Mosaicism"},"content":{"rendered":"<p>Evident in Down&#8217;s syndrome in which there is a mixture of cells containing 46 and 47 chromosomes. &nbsp;Other examples of mosaicism include Edward&#8217;s syndrome and Turner&#8217;s syndrome. &nbsp;It can arise as a consequence of spontaneous DNA mutations, chromosomal abnormalities, and epigenetic changes in chromosomal DNA. &nbsp;The term itself denotes the presence of two or more populations of cells (that may or may not include the germ line cells) in one individual developing from a single fertilized egg. &nbsp;There are in essence two types of mosaicism. &nbsp;In somatic mosaicism, a particular percentage of cells are affected by post-zygotic mutation (cancer being one the most prominent forms of such mosaicism). &nbsp;Somatic mosaicism was first reported by <a href=\"http:\/\/www.nasonline.org\/publications\/biographical-memoirs\/memoir-pdfs\/Stern_Curt.pdf\" class=\"cc-route-enabled\" target=\"_self\" data-editable-link=\"http:\/\/www.nasonline.org\/publications\/biographical-memoirs\/memoir-pdfs\/Stern_Curt.pdf&amp;target=_self\" rel=\"noopener noreferrer\">Curt Stern<\/a> (1902-1981) who demonstrated that when genetic recombination occurs in mitosis it gives rise to this type of mosaicism. &nbsp;Gonadal or germ line mosaicism refers to the presence of a mutation in all of the germ line, but not in the rest of the body, and thus that the mutation occurred in sperm or ova prior to fertilization. &nbsp;The most common of mosaicism revealed by mean of prenatal diagnosis (e,.g., aminocentisis) include those arising from chromosomal mosaicism (e.g., trisomy 21 in Down&#8217;s syndrome). &nbsp;In such cases, trisomy 21 mosaicism can occur in in the germ line, in somatic tissues, or both. &nbsp;There is a lack of information about on the incidence of <a href=\"http:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC3018721\/\" class=\"cc-route-enabled\" target=\"_self\" data-editable-link=\"http:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC3018721\/&amp;target=_self\" rel=\"noopener noreferrer\">mosaicism in Down&#8217;s syndrome<\/a> individuals due to persisting technical problems in its identification, and in part resolved by in situ FISH analysis. &nbsp;Nevertheless, it is estimated that about 2-4% of individuals with Down&#8217;s syndrome have mosaicism for cells with three copies of chromosome 21 (i.e., a combination of normal and trisomy cells within individual tissues).&nbsp; &nbsp; &nbsp;<\/p>\n<p>See <a href=\"amniocentesis\">Amniocentesis<\/a>, <a href=\"chromosome\">Chromosome<\/a>, <a href=\"copying_errors\">Copying errors<\/a>, <a href=\"dna_-deoxyribonucleic_acid-\">DNA (deoxyribonucleic acid)<\/a>, <a href=\"down-s_syndrome\">Down&#8217;s syndrome<\/a>, <a href=\"edward-s_syndrome\">Edward&#8217;s syndrome<\/a>, <a href=\"fluorescent_in_situ_hybridization_-fish-\">Fluorescent in situ hybridization (FISH)<\/a>, Genetic recombination, <a href=\"mitosis\">Mitosis<\/a>, <a href=\"mutation_-biology-\">Mutation (biology)<\/a>, <a href=\"trisomy_21\">Trisomy 21<\/a>, <a href=\"turner-s_syndrome\">Turner&#8217;s syndrome<\/a><\/p>\n<p><\/p>\n<p><\/p>\n<p><\/body><\/html><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Evident in Down&#8217;s syndrome in which there is a mixture of cells containing 46 and 47 chromosomes. &nbsp;Other examples of mosaicism include Edward&#8217;s syndrome and Turner&#8217;s syndrome. &nbsp;It can arise as a consequence of spontaneous DNA mutations, chromosomal abnormalities, and epigenetic changes in chromosomal DNA. &nbsp;The term itself denotes the presence of two or more &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/mosaicism\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Mosaicism&#8221;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[2],"class_list":["post-8462","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-glossary","entry"],"_links":{"self":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts\/8462","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/comments?post=8462"}],"version-history":[{"count":0,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts\/8462\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/media?parent=8462"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/categories?post=8462"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/tags?post=8462"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}